FRANCE - Most fishermen use floats on the headline of their trawls but it is worth considering using kite systems as they do offer some advantages, according to Morgère, the trawl equipment manufacturer.
Michel Dagorn, director of Morgère, says the key benefit is the reduction in drag, which in turn boosts fuel consumption. Kite systems use hydrofoil type arrangements to provide the lift, rather than traditional floats.
Michel Dagorn said: “At Morgère we have patented our own kite system called Aeroplane, which is currently used by a number of fishermen in fishing areas south of Iceland and around Norway. The concept is delightfully simple. The flexible kite, which is made from canvas and coated with tough PVC, is shaped like vents with a larger opening on the front side, which are then arranged in a series along the small meshes of the headline.
“When the trawl is pulled through the sea, the water pressure flowing through the Aeroplane system provides lift, thus opening the trawl. It works very well and fishermen using it have found that it maintains an excellent shape and overall integrity of the net.”
Positioned in the middle of the headline, sea trials have shown that Morgère’s standard Aeroplane (1.50m) does exactly the same job as 35 floats (200mm) at a towing speed of 3.5 knots, or 45 floats at four knots. But for 35 floats there is a drag of around 64kg when towing at three knots. However, by using the 1.5m Aeroplane instead, the drag is reduced to only 32kgs - or half that of the floats. This in turn, produces obvious fuel savings without compromising the effectiveness of the trawl in any way.
The system can be used for bottom, semi-pelagic and pelagic trawls, and an additional advantage is that the Aeroplane is flexible and can easily be stored on the net drum.
Michel Dagorn said: “The Aeroplane, or indeed kite systems in general, may not be suitable for every fisherman, but they are certainly an excellent option worth consideration in many fisheries and we would always be pleased to offer advice.”
TheFishSite News Desk